Optical lighting or signaling devices, such as vehicle lamps, are important components in motor vehicles. Traffic rules and industry standards raise specific requirements on light intensity distribution of light emitted by various vehicle lamps (such as headlights, daytime running lights, brake lights, turn indicators, and so on). Therefore, emergent light beam of the vehicle lamps needs to be adjusted by an optical system before leaving the lamps.
In conventional motor vehicles, vehicle lamps for realizing different functions tend to occupy different spaces, and light exit faces thereof are also independent of each other. Therefore, when a plurality of vehicle lamps for realizing different functions are required, it is definitely necessary to occupy larger spaces, and each individual light exit face can generally only realize a single function. Thus, light emitting areas and spaces of lights for realizing different functions are limited.